This is one of the huge number of Sunni Hadiths prohibiting them from facing their dictators.
It's from 'Sahih Muslim' one of the two most authentic Sunni books after the Quran:
Hudhayfa ibn al-Yaman reported: I asked, “O Messenger of Allah, we were living in an evil time and Allah brought us good which we live in now. Will there be evil after this good?” The Messenger of Allah, peace and blessings be upon him, said, “Yes.” I said, “And any good after this evil?” The Prophet said, “Yes.” I said, “And any evil after this good?” The Prophet said, “Yes.” I said, “How will it be?” The Prophet said, “Rulers after me will come who do not follow my guidance and my tradition (sunnah). Some of their men will have the hearts of devils in a human body.” I said, “O Messenger of Allah, what should I do if I live to see that time?” The Prophet said, “You should listen and obey them even if the ruler strikes your back and takes your wealth, even still listen and obey.”
Source: Sahih Muslim 1847
Grade: Sahih (authentic) according to Sunnis
قَالَ حُذَيْفَةُ بْنُ الْيَمَانِ قُلْتُ يَا رَسُولَ اللَّهِ إِنَّا كُنَّا بِشَرٍّ فَجَاءَ اللَّهُ بِخَيْرٍ فَنَحْنُ فِيهِ فَهَلْ مِنْ وَرَاءِ هَذَا الْخَيْرِ شَرٌّ قَالَ نَعَمْ قُلْتُ هَلْ وَرَاءَ ذَلِكَ الشَّرِّ خَيْرٌ قَالَ نَعَمْ قُلْتُ فَهَلْ وَرَاءَ ذَلِكَ الْخَيْرِ شَرٌّ قَالَنَعَمْ قُلْتُ كَيْفَ قَالَ يَكُونُ بَعْدِي أَئِمَّةٌ لَا يَهْتَدُونَ بِهُدَايَ وَلَا يَسْتَنُّونَ بِسُنَّتِي وَسَيَقُومُ فِيهِمْ رِجَالٌ قُلُوبُهُمْ قُلُوبُ الشَّيَاطِينِ فِي جُثْمَانِ إِنْسٍ قَالَ قُلْتُ كَيْفَ أَصْنَعُ يَا رَسُولَ اللَّهِ إِنْ أَدْرَكْتُ ذَلِكَ قَالَتَسْمَعُ وَتُطِيعُ لِلْأَمِيرِ وَإِنْ ضُرِبَ ظَهْرُكَ وَأُخِذَ مَالُكَ فَاسْمَعْ وَأَطِعْ
1847 صحيح مسلم كِتَاب الْإِمَارَةِ نعم فقلت هل بعد ذلك الشر من خير قال نعم وفيه دخن قلت